beastturbo

I have simply had bc coil overs fitted lowered roughly 20mm from standard Hight and had a fast round geometry set up.
In my opinion I think the geometry set up made a huge difference.

I havnt uprated the arbs as of yet funds allowing I wud go with 22/24 arb and alloy drop links.

Although I can push the car on b roads and made my missis feel car sick. This is something she has never experienced before and she has been a passenger in a lotus Elise at cadwell park

So personally if uv got bcs already get a decent geometry set up first defiantly.

Arnie_1

First of all, apologies to beastturbo for commandeering your thread! We seemed to have taken it over! Sorry.

Nice car!

Unfortunately, I can tell you now, that is going to be an understeering pig!
Sorry if like how it looks now, but if you want to get your car to turn, you'll need to raise your ride height. I would imagine you are experiencing a bit of roll, especially up front because your front roll center is severely compromised. By simply raising your ride height you will experience less roll. Another problem you have at that ride height is your camber curve. You are so low that basically your outside wheel will dip into positive camber in a turn pretty much immediately leaving you with no grip and understeer.

before getting your geometry set I would advise setting your ride height at 360mm F/350mm R. You won't like the looks but it will handle so much better. I actually prefer it even higher (370mmF/360mmR). But the aforementioned is a decent compromise in maintaining geometry and looks.

You're using good tires. The RE070s are a great road/track tire. Great grip and they hold up pretty well. Anyway, since this won't be a daily driver, you can go more aggressive with your alignment for the track.

Take Bonesetter's toe settings above but try using -2.5 camber up front with -2 in the rear. Give that a try and see where you are at on the track. Ideally you'll need to take tire temps to see if you're alignment is optimized but in a pinch, just laying your hand across the face of the tire after a hot lap will let you know if you need more or less camber up front. But I think you'll be needing around -2.5 to -3 up front.

But seriously, try to accept the fact that the geometry of the impreza needs some ride height in order to function properly(unless you change the suspension pickup points). I know that you will look at your car after you raise it and cringe! But trust me, it will handle much much better.

bonesetter

iTrader: (9)

You say Kris will cringe when he sees the new height - I cringed when I saw the present height

I thought I would leave the diplomacy to you Arnie Impreza's just really don't like being lowered

Arnie_1

yeaaahhh, I decided to bite my tongue. But definitely to be filed under "Looks dope, handles like poop!" Sorry Kris!

KrisBuc

iTrader: (2)

No problem lads simple job to raise it up a little but that pic is taken on an incline so front looks lower than really is

beastturbo

Any lower and ul be making my neighbours Saxo look high

I will be measure my ride Hight now to c how close it is to the recommendation of arnie.

Arnie_1

Believe me, most guys think the ride height I run is too high looking. they tend to settle down to around 350mm or so. but, like I say, I don't care how the car looks. I can't see it when i'm going around a corner.

KrisBuc

iTrader: (2)

Raised front last night to 362mm rear to do tonight then alignment Friday

Eacy

iTrader: (9)

Hi all (Arnie) and thanks for all the time U put into this thread.
I am from Denmark (reson for the spelling) and would like to ask a few questions
Got a 1995 jdm wrx. 2.5 forged engine & 6 speed box. Whiteline arbs 22/24, ALK ,solid droplinks ,very soon a corbon roof. My dampers are from KYB AGX and the springs are Eibach red sport line, car is running about 470/470.

The front springs has broken a peace off in the bottom end (dident have bumber stoppes on in the beginning)
The ride hight front is 34,5 cm in left, but only 34 right....
Rear is 33 cm left and 34 right. Why they are differance in the back, I dont know.

I have the 4 wheel alignment done, and it is not far from the one posted here

I know I should change springs, but the sports-line is not for sale anymore, only the softer pro-kit .
I use the car on the Nordsleife in U´r homeland , and that is what I try to set it up for. Beside that it is my daly driver, so dont what it to be to hard.

On The Ring I drive Toyo 888 press. front 1,85 bar rear 1,7 bar.
What would U think to do with the springs?
Cheers Lars

Arnie_1

I know its tough to say without an alignment but did you notice a difference in the handling after raising the ride height? Not sure if you paid attention or not.


Hi Lars - yeah, its getting harder and harder to find decent springs for the Classic. I'm still a big fan of the P1 spring and there might be some on sale in the classifieds here. That would be my top suggestion. Other than that, I would also look into an STi spring from a V5 or V6 (V6 is a bit stiffer). The AGX can handle all of those spring rates. You can order them new from Japan or find them used on some of the UK Subaru parts places (ebay, etc.).

At this point, I can see why people end up going with the BC's as they are readily available and, at least the UK vendor, has spec'd then with decent road spring rates and one version with more travel too. Support also seems to be good. For the money, hard to beat them, though they're not really my cup of java.

Its probably something you don't want to deal with, but the R888's like a bit more negative camber especially if aren't running a stiff spring setup (you'll get more roll compared to normal summer tires as they are much stickier and may get more outside tire wear). With those tires I usually start at about -2.5 camber up front, rear around -1.75 to -2. Thing is that can be a bit aggressive for normal street tires and you may see inside tire wear. So you may have to find a compromise setting that you can use for both road tires and track tires.

KrisBuc

iTrader: (2)

Beastturbo - sorry for commandering your thread

arnie- hi mate never felt no difference after raising the car but massive difference after alignment cheers for the help car feels spot on now !!

chet123

iTrader: (7)

Hello mate, curious to know which alignment settings you followed and for which model car please.

Chet

KrisBuc

iTrader: (2)

Hi mate car is a bug sti
this is the height of the car now lads your right i feel a little in pain when i look at the gaps but ill stick with it and give it a try

this is what my car went into garage with and came out with


car hanldes well but not really pushed it much cheers for the help fellas

Arnie_1

nice! Hard to to tell what your ride heights are due to the slant of the road. Try to take a pic on level ground some time. Just from the visual and to compare, I usually have less fender gap in the rear than on the front. Yours look about even.

Your alignment looks good. Its a mild setup but should give your good tire wear. You won't have as much front end grip when really pushing as you have just over a degree of negative camber. But your shop does nice precise work. Great to find places like that.

bonesetter

iTrader: (9)

Look at these guys drooling at the wheel arch gaps on Burns' WRC

KrisBuc

iTrader: (2)

thats set for gravel though

Markyscoob

Pointless comparing to WRC Cars as the arches are cut back 2-3" compared to a road car. Big carbon wings and rear arches. The only steel left to see is the roof and upper rear wings.... You have to look at the sill line compared to the wheel centres to appreciate a gravel set car probably runs the standard road ride height. Only then can you see how slammed a Tarmac setting is. They'd never get the wheels changed without cutting the arches back otherwise!

bonesetter

iTrader: (9)

Oops, point and missed

KrisBuc

iTrader: (2)

Not here

Arnie_1

Kris, just checking in on you. How's your car feel? have you been able to take it out a bit and flog her?

KrisBuc

iTrader: (2)

Yeah mate feels fine really nice, track day feb 23rd so will have better feel of it then thanks again getting used to ride height now !

Arnie_1

Oh, if you're going to be doing a track day, you will need much more camber than what you currently have up front. I can tell you now you will be miserable and the car will be just understeering a lot at trackday speeds.

If you are planning to be doing trackdays somewhat often you might want to look into choosing a "lazy double" setup on your car.

Basically you will be able to choose between two predetermined settings on the camber plate. You decide how much negative camber you want to run on the track. Say, -2.5 up front. You set this at your camber plate. Mark it with a permanent marker on the plate. Set your front toe to a few minutes toe out. This will be your "track" setting. Then pull the camber back (at the camber plate) until your toe hits what you have now (fast road setting). Then mark the plate. This will be the camber setting for the "fast road". By doing this you can quickly choose between a track day setting and a more mild road setting without having to adjust your toe (which ideally you should do). You just have to jack the front of the car up, loosen your camber plates and carefully nudge the plates inwards or outwards till you hit your markings.

Unfortunately I can't remember how much toe change there is per amount of camber change. You'd need to spend a bit more time with your alignment guy to find the settings you are willing to live with. You may have to decide on which side of the spectrum you want to be at, more aggressive alignment for a track day or less aggressive for the street. You probably won't be able to get the ideal amount for both, it will be a compromise to one way or the other. For example, if you like only -1 deg of fast road neg camber, you may only be able to achieve -1.75 before the toe change is too much. Or if you want -2.5 for the track, you might only be able to achieve -1.5 for the road (with the mild toe setting you have). You'll have to experiment with your alignment guy.

KrisBuc

iTrader: (2)

more camber needed up front cheers again arnie
got my brakes to do so will do them then back for alignment tweak

Arnie_1

What are you planning for your brakes?

Let me know if what I said up above (above marking two settings) is unclear. It was a bit late when i wrote that!

chet123

iTrader: (7)

This topic is very useful and helpful, especially the advise from bonesetter and Arnie_1. Kris_Buc thanks for posting your alignment settings, I'm now able to compare what mines will be against yours. Since Arnie_1 has pointed out good positives from your alignment I have something to try and work towards for my newage.

KrisBuc

iTrader: (2)

Going Godspeed 2 piece discs and orange stuff pads hopefully they will stop me was toying with idea of ksport 330 kit but not in the end

beastturbo

Kris ur alignment setting is very similar to mine, although I have more toe in -8 up front and -2 in rear.


My mate has just had his alignment done and he has -1.10 up front and -1.50 in the rear

Arnie how would this handle he was told it would prevent oversteer? Wat are your thoughts
Not had a chance to give it a good go out yet due to the cold weather. Other mods are whiteline 22mm arb up front, but nothing else???

Arnie_1

ah, good. Make sure you get some proper fluid in there too. Something like Motul RBF600 or ATE Blue. Also make sure you bed in those pads and rotors properly before turning hard laps.


It will handle alright on the road. Its a wee bit more aggressive than an OEM spec alignment and will give him more front end grip and turn in for road use. The basic alignment balance gives a bit more grip to the rear than the front so it won't be prone to oversteer unless provoked. It will start to understeer when really pushing on or if you come in too hot into a corner.

Front end grip for an Impreza on road tires really starts to come alive at about -1.5 up front. But, depending on how often you hit the twisties you may start to see a bit of inside tire wear if you don't use zero toe up front. So you just need to be honest and realistic about how you really drive and set your alignment accordingly. If you know that you're going to be driving 99.9% of time on the motorways, it makes no sense to run massive negative camber, for example. Though, to be honest, -1 is about the minimum I'd ever run on a mixed use car (motorway/b-road twisties). Front OEM camber bolt will net you about -1.5 maximum with lots of tugging. And the difference between even half a degree extra neg camber (say, -1 and going to -1.5) is quite a bit in regards to front end stick. You guys should try it some time, i.e. learn to do your own alignments at home!

bonesetter

iTrader: (9)

I would say your mate's been given a 'safe' geo. 'Preventing oversteer' also infers a bias toward understeer, which is 'the factory setting' or in other words best for the average driver.

Of course, different folk have have different preferences. Some may like understeer at the limit, others oversteer, or neutral. Personally I prefer a rock solid laser sharp front, with the rest of the balance being neutral, and a little rotation if provoked. Those geo figures would err on the side of more negative camber front, say -1 3/4°F/-1.5°R. That sort of ratio anyway, camber bolts blah blah

Edit: Posted at the same time as Arnie...

Markyscoob

What we REALLY need is a setup chart that let's us see the toe change per turn./half turn of tie rod. Then when you have the GEo done you know where you are. Then we need to know the toe change per degree of camber. However, as the camber change is either by camber bolt or top adjust, the toe change will be massively different for each.

Only works with a friendly geo guy as they MUST know giving the data out will cost them repeat work!!!

Would you?

Mine's now 355R/365F and I can really feel the increased front roll and change in roll axis from O.E. I do like the fact that without changing anything else, I can alter balance in roll with front ride height and resultant roll centre and axis changes.

I actually have deduced from this, the obvious that higher is better!

I've also dropped Peter Cambridge a line on the matter.

The reason Imprezas' don't like dropping is the roll centre on a McPherson strut drops like the Titanic with ride height drop. Not good but unavoidable unless you fit a RCC kit.

I suggested an infinitely adjustable shimmed design he could get made and market. I'd definitely be interested in being able to shim my lower balljoint/ to lower arm fitting to alter roll centre independantly of ride height.

Arnie,

Let's have a summary if you can.

Road O.E. ride height, toe and camber f/r
Fast road """"
Track """"